The present invention relates to pre-cast concrete building components capable of assembly into constructional superstructures. The invention, more particularly, relates to a pre-cast portal frame adapted for manufacture as discreet components to thereby provide for later assembly at a construction site.
The use of concrete portal frames in building construction is well known. However, the use of such concrete portal frames has not become wide spread due to the high cost of erecting a monolithic concrete portal unit. Such a monolithic unit is awkward to cast at the site of construction and is cumbersome to erect. Further, if it is poured at a distance from the construction site, the transportation thereof is costly.
Concrete portal frames of the inventive type may be employed either to define an entrance to a structural wall or, alternatively, to provide a means for bearing the overall weight of the roof of the structure.
The prior art, as best known to the inventor, is represented by U.S. Pat. No. 2,409,383 (1946) to Pedersen, entitled Frame Structure. Pederson, however, relates to woodframe construction, as opposed to pre-cast concrete construction which is the focus of the instant invention. Further, Pederson does not provide for the form of key interlock taught by the within invention.
Other prior art known to the applicant is U.S. Pat. No. 4,725,611 (1985) to Basset; U.S. Pat. No. 4,815,242 (1986) to Gilliland; and U.S. Pat. No. 4,435,938 (1986) to Scott.
Other, further removed prior art known to the applicant is French Patent No. 2,587,745 (1987) to Gonzalez; and Czech Patent No. 78832 (1950) to Kozeny.
It is in response to the long felt need for a prefabricated, pre-cast concrete portal frame system that the present invention is directed.
Other prior art known to the applicant comprises United Kingdom Patent No. 570,151 (1943) to Dingsdale. Said patent relates to an improvement in the construction of greenhouses and the like, and differs from applicant's structure in that it does not provide any enlarged dimension at the upper portion of the vertical portions thereof or at the apex to thereby buttress against bending moments to which any such resultant system is susceptible.